The FN12-12D/630-20 series high-pressure gas-type load break switch (hereinafter referred to as the FN12-12D load switch) is a three-phase high-voltage switching device with a rated voltage of 12kV and a rated frequency of 50Hz. It is used for switching load currents, closed-loop currents, no-load transformers, and cable charging currents, as well as closing short-circuit currents. Load switches equipped with grounding switches can withstand short-circuit currents.
The FN12-12D/125-31.5 series high-pressure gas-type load break switch-fuse combination apparatus (hereinafter referred to as the FN12-12D combination apparatus) is an indoor high-voltage switching device that combines the FN12-12D load switch with the S□LAJ-12 (XRNT□-10) high-voltage current-limiting fuse. It can reliably interrupt any current up to short-circuit currents; the load switch interrupts operating currents, the fuse interrupts short-circuit currents, and together they interrupt any overcurrent between operating currents and full short-circuit currents. Simultaneously, the fuse triggers the load switch to open via its striker.